1989 MITSUBISHI GALANT check engine

FUEL SYSTEM -On-Vehicle Inspection
of
MFI
Components13-295
Filter
Connector
Solenoid coil
Plunger
Needle valve -&$
lnjedtion6FUO51
Multiport
fuel injection relayMIBvrbA1
I
The area enclosed with ~~~~ is@I Harness side
applicable onlv for Turbo.
connector
Enginecofitrolmodule
Engine control module connectorI6FU1547
OlLo63
OPERATION
l The injectorsare electromagnetic-valve-
equipped injection nozzles that function to inject
fuel based upon injection signals from the engine control module.
lBecause the surface area of the injection ports is
fixed and because the pressure of the fuel relative to the pressure within the manifold is
also regulated to a fixed pressure, the amount of
fuel injection by injectors is determined by the
TROUBLESHOOTING HINTS
Hint 1:
If there is a problem with starting while the engine is
warm, perform the combustion test and check for leakage of the injectors.Hint 2:
If the engine can’t be started, and the injectors are
not activated during cranking, the cause is probably
a malfunction such as described below, not with the injectors.
(1) Malfunction of the circuit for supply of power to
the engine control module, or of the ground cir-
cuit.
(2) Malfunction of the multiport fuel injection relay.
(3) Malfunction of the crankshaft position sensor and/or the camshaft position sensor.
Hint 3:
If there is a cylinder for which the idling condition
does not change when, during idling, the fuelinjection of the injectors is cut off in sequence,
length of time that the needle valve is open, or,
in other words, by the length of time of current
flow to the solenoid coil.
lBattery power supply is supplied, by way of the
multiport fuel injection relay, to the injectors.
When the engine control module switches ON
the power transistor within the unit and current
flows to the solenoid coil, the injectors open and
fuel is injected.
check that cylinder as described below.
(1) Check the injector and harness.
(2) Check the spark plugs and the high-tension
cable.
(3) Check the compression pressure. Hint 4:
if the injector activation time deviates from the
standard value even though the results of the
checking of the injector’s harness and of the injector
itself are normal, the cause may be pressumed to
be one of the following,
(1) Incomplete combustion within the cylinder.
(Malfunction of the spark plugs, the ignition coil,
the compression pressure, etc.)
(2) Incomplete close contact of the EGR valve seat.
(3) Increased engine resistance.
TSB Revision

13-296FUEL SYSTEM -On-Vehicle
Inspection
of
MFI
Components
INSPECTION
Using Scan tool
Function Item No. Data displayInspection conditionsEngine coolant temperature Standard value1
Data 41;ctJ$onEngine crankingAt 0°C (32”F)*2Approx. 17 ms
readingApprox. 40 ms
At 20°C (68°F)Approx. 38 ms
Approx. 19 ms
At 80°C (176°F)Approx. 9 ms
Approx. 4.5 ms
Function
Datareading
3TE Item No.
41
Data display
$ctX$on
Inspection conditionsEngine condition
Standard value
. Engine coolant tempera-Idling2.4-3.2 ms
ture:1.6-2.6 ms 85-95°C
(185-205°F)
. Lights, cooling fan, electric- 2,000 rpm1.9-2.9
ms
al accessories: OFF1.4-2.2 ms . Transaxle: neutralDuring sudden Increasesracing
+l:The injector activation time indicates the time under the following cond\
itions: a power source voltage of 11V and acranking rpm of 250 rpm or less.*2: Simultaneous injection at four cylinders when engine coolant temperatur\
e is 0°C (32°F).*3: The injector activation time may be about 10% longer than indicated abo\
ve when the vehicle is new [driven
approximately 500 km (300 miles) or less].
Function Item No.Description Inspection conditionsNormal indication
Actuator test 01No. 1 injector is shut off.
Engine: idling after warmThe idling condition
02No. 2 injector is shut off.?!hut off the injectors inchanges more.
(Either becomes more un-
03
No. 3 injector is shut off.
04
No.4 injector is shut off.
sequence during after
engine warm-up, check
the idling condition.) stable, or engine stalls.)
,d&- A: InjectorNormal wavetormdrive time
HARNESS INSPECTION

@ Harness sideconnector
I
L
Using Oscilloscope
(1) Run the engine at idle speed.
(2) Connect the probe to the oscilloscope pick-up point as
shown in the circuit diagram, and check the waveform at
the drive side of each injector.
Measure the power supply voltage ofthe resistor.
. Connector: Disconnected. Ignition switch: ON
1 TSB hevision

FUEL SYSTEM - On-Vehicle
inspection
of MFI
Components13-297
@I Harness sideconnector
Measure the power supply voltage of
the injector.
. Resistor connector: Connected
. Injector connector: Disconnected
. Ignition switch: ON
module harness
side connecror
ACTUATOR INSPECTION
INJECTOR
CHECKING OPERATION SOUND
Using a sound scope, check the operation sound (“chi-chi-chi”)
of injectors during idling or during cranking.
Check that as the rotating speed increases, the frequency of
the operating sound also increases.
Caution
Note that even if the injector you are checking is not
operating, you will hear the operating sound of the other
injectors.
NOTE
If no operating sound is heard from the injector that is being
checked, check the injector drive circuit. If there is nothing
wrong with the circuit, a defective injector or engine control module is suspected.
MEASURING RESISTANCE BETWEEN TERMINALS
(1) Remove the injector connector.
(2) Measure the resistance between the terminals.
Standard value:
13-16 Sz [at 20°C (68”F)I
2-3
Q [at 20°C (68”F)] >
(3) Install the injector connector.
1 TSB RevisionI

FUEL SYSTEM -On-Vehicle Inspection of
MFI Components13-299
OPERATION
l The amount of air taken in during idling is
regulated by the opening and closing of the
servo valve located in the air passage that
bypasses the throttle valve.
l The servo valve is opened or closed by the
activation of the stepper motor (incorporated
within the idle air control motor) in the forward
or reverse direction.
TROUBLESHOOTING HINTS
Hint 1: If the number of stepper motor steps increases to
IOO- 120 steps or decreases
to 0 step, the cause may be presumed to be a malfunction of the stepper motor or
damaged or disconnected wiring of the
harness.
Hint 2: If the number of stepper motor steps
deviates from the standard value even
though the results of the checking of the
harness of the idle air control motor and of
the comoonent
itself indicate no abnormal
condition, the cause may be presumed to be one of the following.
INSPECTION
Using Scan tool
lBattery power supply is supplied, by way of the
multiport fuel injection relay, to the coil of the
stepper motor. The engine control module
switches ON the power transistors (located
within the engine control module) in sequential
order, and, when current flows to the stepper motor coil, the stepper motor is activated in the
forward or reverse direction.
(1) Improper adjustment of the standard
idling speed.
(2) Deposits adhered to the throttle valve.
(3) Leakage of air into the intake manifold
from a gasket gap, etc.
(4) Incomplete close contact of the EGRvalve seat.
(5) Incomplete combustion within the
cylinder.
(Malfunction of the spark plugs, the
ignition coil, the iniectors,
the
com- pression
pressure, etc.)
FunctionItem No.Data display Check conditions Load conditionsStandard value
Data reading 45Steppermotor steps. Engine coolant tempera-
. Air conditioning
4-14Step
ture:switch: OFF 85-95°C

(185-205°F)
. Lights, electrical cooling
:$b::pfan and accessories: OFF
. Transaxle: neutral
. Closed throttle switch: ON
- Air conditioning 20-60 Step
switch: ON
(The compressor clutchshould be activated when
the air conditioning switch;J-;;o~P
is switched ON.)* Engine: idling
1;:!,1;:!,
/!-I\/!-I\
f$&$:”f$&$:”
! ,‘,! ,‘,
4);4);
;jj\(Q(j!jGZ-);jj\(Q(j!jGZ-)
lili
q#Q~Hq#Q~HF]F]
ii 2 L J 2 L ~ -0SClllO 4ii 2 L J 2 L ~ -0SClllO 4
NOTE
When the vehicle is new (driven approximately 500 km (300 miles) or l\
ess) the number of steps may be about
30 steps greater than the standard value indicated above.
Using Oscilloscope
(1) Connect the probe to each oscilloscope pick-up point as
shown in the circuit diagram.
(2) Start the engine.
(3) When the air conditioning switch is turned on, the idling speed increases to operate the idle air control. Check theinstantaneous waveform.
NOTE
Keep in mind that the waveform can be observed only
when idle air control is in operation.

FUEL SYSTEM - On-Vehicle Inspection
of
MFI Components
HARNESS INSPECTION
connector
@ Harness side7
connectorharnessside connw&
cI
7FUOOlO
Measure the power supply VOltage ofthe idle air control motor.
. e Idle air control motor connec-tor: Disconnected. Ignition switch: ON
Check for an open-circuit, or a short-circuit to ground, between the enginecontrol module and idle air controlmotor.
. Engine control module connec-tor: Disconnected* Idle air control motor connec-‘--R&heharness.tor: Disconnected
ACTUATOR INSPECTION
Checking the Operation Sound
(1) Check that the operation sound of the stepper motor can
be heard after the ignition is switched ON (but without
starting the motor).
(2) If the operation sound cannot be heard, check the stepper
motor’s activation circuit.If the circuit is normal, it is probable that there is a
malfunction of the stepper motor or of the engine control
module.
Checking the Coil Resistance
(1) Disconnect the idle air control motor connector and con- nect the special tool (Test harness).
(2) Measure the resistance between terminal
@ (white clip of
the special tool) and either terminal
@ (red clip) or terminal
$d;!lue clip) of the connector at the idle air control motor
Standard value: 28-33 &
at
20°C (68°F)
(3) Measure the resistance between terminal @ (green clip of
the special tool) and either terminal
@ (yellow clip) or ter-
minal
@ (black clip) of the connector at the idle air control
motor side.
Standard value: 28-33
51 at 20°C (68°F)
J
TSB Revision

r
FUEL SYSTEM -On-Vehicle Inspection
of
MFI Components13-303
INSPECTION
Using Scan tool
Function Item No.
Data reading 44
Data displayInspection conditionsEngine condition Standard value
Ignition
advance
. Engine: warm
. Timing light: set750 rpm (idling)5-15” BTDC
(Use the timing light to
check the actual ignition 2,000 rpm32 - 4 1 “BTDCtiming.)
Oscillo 1
Normal waveform
Oscilio 2
!
1ov --
-
ovNormal waveform
HARNESS INSPECTION
Harness side
connectorE 0-0
J
El0
connectorI
lEnginecontrol
module
harness
sideconnector
Using Oscilloscope
1. Primary signal of ignition coil
(1) Run the engine at an idle revolution speed.
(2) Connect the probe to oscilloscope pick-up point
1 as
shown in the circuit diagram, and check the primary
signal of the ignition coil.
2.Control signal of ignition power transistor
(3) Connect the probe to oscilloscope pick-up point 2 as
shown in the circuit diagram, and check the control
signal of the ignition power transistor.
Measure the power supply voltage ofthe ignition coil.
. Connector: Disconnected. Ignition switch: ON
Voltage (VI
IBattery positive voltageIIIgnitionswitch)
Check for an open-circuit, or a
short-circuit to ground, between the engine
control module and the ignition coil.
* Engine control module connec- tor: Disconnected
* Ignition coil connector: Discon-nected
i
Repair theharness.
N23l3k-m)
TSB Revision

13-306FUEL SYSTEM - On-Vehicle
Inspection
of
MFI
Components
Harnesscirio
-.-.,@ connector
Measure the power supply voltage ofthe ignition coil.
. Connector: Disconnected. Ignition switch: ON
HARNESS INSPECTION
Harness side
I
Measure the power supply voltage ofthe ignition coil.
. Connector: Disconnected. ignition switch: ON
control module and the ignition
power transistor.
. Engine control module connec-tor: Disconnected. Ignition power transistor connec-tor: DisconnectedRepair theharness.
KI3zil-m)
6FU1387I
t III1an open-circuit, or a short-ground, between the igni-
power transistor and the ignition
coil connector: Discon-
* Ignition power transistor connec-tor: DisconnectedReoair the
t
hamess.
KBEI-GUI~GZWBXZl)
IJ
5
Harness side@ connector
J
TSB Revision
Check for continuity of the groundcircuit.
. Connector: Disconnected

13-308FUEL SYSTEM - On-Vehicle Inspection
of
MFI
Components
OPERATION
l
The fuel pressure solenoid is an ON-OFF type of
solenoid valve and changes pressure fed into
the fuel pressure regulator to intake manifold
pressure and barometric pressure.
l Battery power is supplied to the fuel pressure
solenoid via the multiport
fuel injection relay.
When the engine control module turns on the
power transistor in the unit, current flows in the
coil and barometric pressure is fed to the fuel pressure regulator.
INSPECTION
Using Scan tool
0 If engine coolant temperature (approximatel
y
95°C (203°F) or more) and also air intake
temperature (approximately
50°C (122°F) or
more) are high when the engine is started, fuel
pressure is controlled in order to maintain
pressure at approximately 260
kPa (37 psi)
immediately after starting and then, after a lapse
of approximately 30 seconds to 2 minutes, to lower it to approximately 190
kPa (27 psi).
Function Item No.
Actuator test 09
DescriptionInspection conditionsNormal condition
$$;;i;;;alve switched fromIgnition switch: ONOperating sound is
heard when driven.
HARNESS INSPECTION
Harness side
Measure the power supply VokW 1
. Connector: Disconnected 1
. Ignition switch: ON
Voltage 04
1 Battery positive voltage 1t)lt<
02
Repair theharness.
@I4,MFI
Engine control module
harness side connecto
Harness side
Check for an open-circuit, or shot-t-circuit to ground, between the fuel
pressure solenoid and the engine
control module.
- Engine control module connec-tor: Disconnected. Fuel pressure solenoid connec-tor: DisconnectedRepair theharness.
h25xwzl21,
1 TSB Revision